Joke: It's Not Working Properly

I bought an alarm clock yesterday but I took it back today and asked for a refund, I said to the assistant, “It’s not working properly, I set the alarm for 7:30am but it went off at 4:30am.”

“I’d like to give you a refund sir, but it’s smashed into pieces.

How do you explain the damage?” he asked.

I said, “I just told you, it’s not working properly and it went off at 4:30am.”